Home / Accessories / Extra Whistle View cart “CR123 Batteries (4 pk)” has been added to your cart. Extra Whistle $10.00 In stock Extra Whistle quantity Add to cart SKU: Extra Whistle Category: Accessories Description The extra 12-volt DC whistle can be connected to the receiver to make it louder, or it can be located in another room or building by wiring it with two-strand doorbell wire. Related products P-50 Replacement Probe w/ 50′ Wire $75.00 Add to cart P-125 Replacement Probe w/ 125′ Wire $99.00 Add to cart 25′ Rubber Hose $35.00 Add to cart P-250 Replacement Probe w/ 250′ Wire $149.00 Add to cart