Click to expand Tap to zoom HARTZ® ULTRAGUARD® FLEA & TICK COLLAR FOR DOGS by HARTZ® Save Liquid error (product-badge line 32): Computation results in '-Infinity'% $6.09 SKU F012-51559 Regular - $6.09 Large - $6.69 Regular Large Size 1 2 3 4 5 6 7 8 9 10+ Quantity Quantity Add to cart Slow-release collars kills fleas for up to 5 months and ticks for up to 4 months.