Inclusion Criteria:
* Have a BMI ≥ 27;
* Be male or female, between 18 and 65 years of age, inclusive;
* Have a history of excess weight (BMI ≥ 27 kg/m2) for at least 2 years and have failed more conservative weight-reduction alternatives, such as supervised diet, exercise and behavioral modification programs;
* Be willing to commit to a long-term low calorie (1000-1500 calories/day) supervised diet;
* Have reasonable weight loss expectations (accept a goal of losing up to 15% of body weight after 52 weeks);
* Be able to follow requirements outlined in the protocol, including complying with the visit schedule and behavioral modification program, and willing to undergo protocol-specific procedures, e.g., endoscopy, local sedation, general anesthesia, upper gastrointestinal radiography (UGI), electrocardiography (EKG), gastric motility testing, and/or clinical laboratory testing, and must be willing to take prescribed proton pump inhibitors (PPIs);
* Be able to provide written informed consent;
* Have successful completion of the pre-placement screening and educational programs supporting that the subject is an appropriate study candidate;
* Be willing to use contraception (e.g., birth control pills, condoms, abstinence) and avoid pregnancy during the study if female of child-bearing potential.
Exclusion Criteria:
* Previous history of esophageal, gastric or duodenal surgery, any bariatric surgery, any hiatal hernia surgery, bowel obstruction surgery, adhesive peritonitis, and/or hiatal hernia \> 4 cm;
* A history of myocardial infarction in the previous 6 months: New York Heart Associate (NYHA) Class III or IV (heart failure) or cardiac arrhythmia (e.g. atrial fibrillation);
* History or symptoms of varices, bowel obstruction, congenital or acquired GI anomalies (e.g., atresias, stenosis, stricture, and/or diverticula), severe renal, hepatic, and/or pulmonary disease;
* History or symptoms of inflammatory bowel disease, such as Crohn's disease;
* History of unstable thyroid disease;
* History of uncontrolled gastro-esophageal reflux;
* Type I diabetes;
* History of dysphagia, esophageal stricture or esophageal food impaction;
* Poor general health, in the opinion of the Placing and/or Evaluating Investigator, or presence of a specific medical condition that would increase the risks associated with endoscopy and/or placement of the Spatz4;
* Symptomatic congestive heart failure, cardiac arrhythmia or unstable coronary artery disease.
* Pre-existing respiratory disease such as chronic obstructive pulmonary disease (COPD);
* Specific diagnosed genetic or hormonal cause for obesity such as Prader Willi syndrome
* History or symptoms of esophageal or GI motility disorders (e.g., gastroparesis, achalasia, diffuse esophageal spasm) or symptoms of esophageal stricture;
* Ongoing treatment with anticoagulants, steroids, aspirin \> 100 mg, non-steroidal anti-inflammatory drugs (NSAIDS), or other medications known to be gastric irritants, and inability or unwillingness to discontinue the use of these concomitant medications;
* Evidence of untreated psychiatric or eating disorders, such as major depression, schizophrenia, substance abuse;
* Pregnancy, breast-feeding, or intention of becoming pregnant during the study (if female of childbearing potential);
* A condition, or is in a situation, which in the Evaluating and/or Placing Investigator's opinion may put the subject at significant risk, may confound the study results, or may interfere significantly with the subject's participation in the study.
