Ring modulator effects&colon; Moogerfooger MF-102 Ring Modulator. The MF-102 is an analog ring modulator. Tamoxifen is a selective estrogen receptor modulator (SERM). Ormeloxifene is a selective estrogen receptor modulator (SERM). Clomifene is a selective estrogen receptor modulator (SERM). Methylphenylpiracetam is a positive allosteric modulator of the sigma-1 receptor. Carbidopa is a selective aryl hydrocarbon receptor modulator (SAhRM). Allopregnanolone acts as a highly potent positive allosteric modulator of the GABA receptor. The compound SB269652 is a negative allosteric modulator of the D2R. RO4491533 acts as a negative allosteric modulator of mGluR and mGluR. It acts as a GABAergic agent and as a positive allosteric modulator of GABA receptor. It is a third-generation selective estrogen receptor modulator (SERM). Eszopiclone acts on benzodiazepine binding site situated on GABA neurons as a positive allosteric modulator. The infinite bandwidth is caused by the nonlinear operation of the pulse-width modulator. It is also known to be a negative allosteric modulator at CB1.